If you were really compelled to question everything around, then you'd be asking why blah and blah is blah, and blah blah, and blah blah blah, and fifty million other things every other second.

As for your little "why do we blah" thing, it's because we can. Just like we can kill, eat, sleep, drink, etc. We have the power to do it, and with that power to do it we choose to do it. Yup..nope? Okay...